Samples are documented to be available every 0.667us, so in theory the 8 sample deep FIFO should take 5.336us to fill. However, during thorough testing, it became apparent that filling the FIFO actually takes closer to 12us.
Signed-off-by: Lee Jones <[email protected]> --- drivers/char/hw_random/st-rng.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/char/hw_random/st-rng.c b/drivers/char/hw_random/st-rng.c index 8c8a435..a1ff080 100644 --- a/drivers/char/hw_random/st-rng.c +++ b/drivers/char/hw_random/st-rng.c @@ -32,8 +32,13 @@ #define ST_RNG_FIFO_SIZE 8 #define ST_RNG_SAMPLE_SIZE 2 /* 2 Byte (16bit) samples */ -/* Samples are available every 0.667us, which we round to 1us */ -#define ST_RNG_FILL_FIFO_TIMEOUT (1 * (ST_RNG_FIFO_SIZE / ST_RNG_SAMPLE_SIZE)) +/* + * Samples are documented to be available every 0.667us, so in theory + * the 8 sample deep FIFO should take 5.336us to fill. However, during + * thorough testing, it became apparent that filling the FIFO actually + * takes closer to 12us. + */ +#define ST_RNG_FILL_FIFO_TIMEOUT 12 struct st_rng_data { void __iomem *base; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
